Problem: $ { \left[\begin{array}{rrr}{2} & {0} & {4} \\ {1} & {4} & {-1}\end{array}\right]-\left[\begin{array}{rrr}{4} & {1} & {-2} \\ {-1} & {-2} & {-2}\end{array}\right] = {?} } $
Explanation: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rrr}{2}-{4} & {0}-{1} & {4}-{-2} \\ {1}-{-1} & {4}-{-2} & {-1}-{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-2} & {-1} & {6} \\ {2} & {6} & {1}\end{array}\right]}$